Solenoid valve current calibration control method considering temperature influence

Abstract

The invention relates to the technical field of electromagnetic valve current control, and discloses an electromagnetic valve current calibration control method considering temperature influence, which comprises the following steps: S1, establishing an electromagnetic valve current dynamic model; s2, constructing a temperature-dependent coil resistance model; s3, setting an optimal control target of electromagnetic valve current calibration; s4, solving an optimal pulse width modulation duty ratio based on an HJB equation; and S5, electromagnetic valve current calibration control is implemented based on the optimal pulse width modulation duty ratio. The dynamic pulse width modulation frequency adjusting strategy is adopted, the pulse width modulation frequency is adjusted in a self-adaptive mode in combination with the current error and the temperature change rate, the switching loss is reduced, meanwhile, the current stability is ensured, compared with an existing fixed pulse width modulation frequency scheme, the loss of a high-frequency switch is reduced, the energy utilization rate is optimized, and the power consumption is reduced. The problem of extra heat loss caused by high-frequency driving is solved, and the energy efficiency ratio of the system is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solenoid valve current control, and specifically to a solenoid valve current calibration control method considering the influence of temperature. Background Art

[0002] As an important actuator in an automated control system, the working stability of a solenoid valve directly affects the overall performance of the system. In many application scenarios, such as precision fluid control, automatic transmissions, and hydraulic systems, the solenoid valve requires precise current control to ensure response speed and execution accuracy. The temperature factor has a significant impact on the current control of the solenoid valve, mainly manifested as the coil resistance changes with temperature, resulting in current drift, which in turn affects the magnetic field strength and valve switching characteristics.

[0003] To compensate for the influence of temperature, existing technologies mainly adopt fixed parameter calibration, offline temperature compensation, or simple open-loop pulse width modulation control methods. However, these methods have many limitations. Especially in high-dynamic load or extreme temperature environments, both the control accuracy and energy efficiency ratio are affected. Therefore, researching a solenoid valve current calibration control method that can consider the influence of temperature in real time has become the key to improving the system reliability and energy-saving characteristics.

[0004] Currently, most solenoid valve control systems drive with a fixed pulse width modulation frequency, usually selecting a suitable frequency based on experience or device specifications. The fixed frequency strategy cannot dynamically adapt to temperature changes and current errors, resulting in maintaining a high frequency switch at low loads, increasing switching losses. At the same time, it will cause additional heat accumulation under high-temperature conditions, reducing the system efficiency. In addition, the fixed frequency cannot balance the requirements of high-speed response and low power consumption, resulting in the system not achieving the best performance under different working conditions.

[0005] Currently, some solenoid valve systems adopt PID control or current compensation methods set based on experience to reduce the influence of temperature on current control. However, the PID algorithm is prone to overshoot or lag when dealing with non-linear temperature changes and cannot quickly adapt to temperature fluctuations. Importantly, traditional PID control requires manual parameter tuning and needs to be re-tuned under different working conditions, lacking universality. The empirical parameter adjustment method depends on a specific environment and has poor adaptability to complex dynamic working conditions, resulting in a decline in control accuracy and stability.

[0006] In summary, the traditional solenoid valve current control methods have the energy consumption problem caused by the fixed pulse width modulation frequency strategy and the poor adaptability of PID control under complex working conditions. Therefore, a solenoid valve current calibration control method that can dynamically adapt the pulse width modulation frequency and perform high-speed closed-loop optimization control is needed to improve control accuracy, energy efficiency ratio, and environmental adaptability.

[0007] Based on the above problems, the present invention proposes a solenoid valve current calibration control method considering temperature effects. Through adaptive pulse width modulation frequency adjustment and an optimal control algorithm, high-precision and low-power consumption solenoid valve current control is achieved, effectively solving the limitations of the prior art. Summary of the Invention

[0008] In view of the deficiencies of the prior art, the present invention provides a solenoid valve current calibration control method considering temperature effects to solve the problems raised in the above background technology.

[0009] To achieve the above objectives, the present invention is realized through the following technical solutions: A solenoid valve current calibration control method considering temperature effects, including:

[0010] Step S1: Establish a solenoid valve current dynamics model;

[0011] Step S2: Construct a temperature-dependent coil resistance model;

[0012] Step S3: Set the optimal control objective for solenoid valve current calibration;

[0013] Step S4: Solve the optimal pulse width modulation duty cycle based on the HJB equation;

[0014] Step S5: Implement solenoid valve current calibration control based on the optimal pulse width modulation duty cycle.

[0015] Preferably, in the step S1, further including in establishing the solenoid valve current dynamics model:

[0016] Step 1.1, use Kirchhoff's voltage law to construct a solenoid valve current dynamics model to determine the relationship between the solenoid valve coil current, inductance, resistance, supply voltage, and pulse width modulation duty cycle;

[0017] Step 1.2, establish a differential equation to describe the dynamic influence of the pulse width modulation duty cycle on the current, and the differential equation is expressed as:

[0018] where, I(t) is the solenoid valve coil current, R(T) is the resistance at temperature T, D(t) is the pulse width modulation duty cycle, L is the inductance of the solenoid valve coil, and U is the supply voltage;

[0019] Step 1.3, combine with the temperature-dependent resistance model to ensure that the current dynamics model can be adjusted by temperature changes.

[0020] Preferably, in the step S2, further including in constructing the temperature-dependent coil resistance model:

[0021] Step 2.1, based on the experimental data, fit the relationship between the temperature T and the coil resistance R to obtain a temperature-dependent model: R(T) = R0(1 + α1(T - T0) + α2(T - T0) 2 )

[0022] where R0 is the resistance at the reference temperature T0, α1 and α2 are temperature coefficients, T is the current temperature, T0 is the reference temperature, and R(T) is the coil resistance at temperature T;

[0023] Step 2.2, in combination with the current dynamics model, substitute the temperature model and dynamically adjust the resistance parameters to ensure that the model can provide accurate resistance change information for setting the optimal control target.

[0024] Preferably, in step S3, setting the optimal control target for solenoid valve current calibration further includes:

[0025] Step 3.1, according to the models in step S1 and step S2, define the optimization objective function, considering the current error term and the energy consumption term. The objective function is:

[0026]

[0027] where I * is the target current, I(t) is the actual current, D(t) is the pulse width modulation duty cycle, w1 is the weight of the current error, w2 is the weight of the energy consumption, J is the optimization objective function, and t f is the termination time of the optimization process;

[0028] Step 3.2, set the optimization constraint conditions to ensure that the maximum current and power of the solenoid valve are limited within a safe range and provide an optimization criterion for solving the optimal pulse width modulation duty cycle.

[0029] Preferably, in step S4, solving the optimal pulse width modulation duty cycle based on the HJB equation further includes:

[0030] Step 4.1, in combination with the optimization objective function, derive the HJB equation, construct the optimal value function V(x1, x2, t) and solve the optimal pulse width modulation duty cycle D * (t). The HJB equation is as follows:

[0031]

[0032] where V(x1, x2, t) is the optimal value function, x1 = I(t) is the current current, x2 = T(t) is the current temperature, u = D(t) is the control variable, w1 is the weight coefficient of the current error, w2 is the weight coefficient of the energy consumption, R(x2) is the coil resistance dependent on the temperature x2, L is the solenoid valve coil inductance, U is the supply voltage, and f tModel for the influence of temperature change on current dynamics;

[0033] Step 4.2: Combine the temperature model in Step S2 to ensure that the pulse-width modulation duty cycle obtained by solving can dynamically adapt to temperature changes and meet the optimization objective in Step S3;

[0034] Step 4.3: Solve for the optimal pulse-width modulation duty cycle D * (t) through the optimal control theory and provide an optimal control signal for current calibration control.

[0035] Preferably, in Step S5, the solenoid valve current calibration control based on the optimal pulse-width modulation duty cycle further includes:

[0036] Step 5.1: Use the optimal pulse-width modulation duty cycle obtained in Step S4 to dynamically adjust the pulse-width modulation signal so that the actual current gradually approaches the target current;

[0037] Step 5.2: Combine the temperature-dependent resistance model in Step S2 to compensate in real time for the influence of temperature changes on the pulse-width modulation duty cycle;

[0038] Step 5.3: Transmit the adjusted pulse-width modulation signal to the solenoid valve drive circuit to achieve precise current calibration control and ensure that the optimization objective set in Step S3 is met.

[0039] Preferably, the solenoid valve current calibration control method is applicable to various different types of solenoid valve systems and adapts to the working characteristics of different solenoid valves by adjusting parameters.

[0040] Preferably, to adapt to different solenoid valve systems and dynamically parameterize the key characteristics of solenoid valves, an adaptive adjustment algorithm is used;

[0041] The parameter adaptive adjustment formula

[0042]

[0043] where θ i is the solenoid valve system model parameter, γ i is the parameter adjustment learning rate, J is the optimization objective function, is the partial derivative of the objective function with respect to the parameter, is the old parameter of the solenoid valve system model, is the new parameter of the solenoid valve system model.

[0044] Preferably, the pulse-width modulation control frequency of the solenoid valve current calibration control method can be set according to specific application requirements to adapt to different control precision and current stability requirements.

[0045] Preferably, according to the requirements of control accuracy and current stability, the pulse width modulation frequency f is dynamically adjusted. PWM The dynamic adjustment pulse width modulation frequency model is as follows:

[0046] Based on the current error and the temperature change rate:

[0047]

[0048] Frequency selection based on the optimized control model:

[0049]

[0050] Switching loss model caused by frequency:

[0051] P switch (f PWM ) = E on ·f PWM + E off ·f PWM ,

[0052] where f PWM (t) is the real-time frequency of the pulse width modulation signal, f min , f max are the upper and lower limits of the pulse width modulation frequency, σ is the normalization function, k e is the current error weight coefficient, k T is the temperature change rate weight coefficient, J freq is the frequency optimization objective function

[0053] w1, w2, w3 are the weights of different factors in the optimization objective function, E on , E off are the energies lost in each switching process, P switch (f PWM ) is the switching power loss caused by the pulse width modulation frequency, I * is the target current, I(t) is the actual current, and T(t) is the current temperature.

[0054] The present invention provides a solenoid valve current calibration control method considering the influence of temperature. It has the following beneficial effects:

[0055] 1. The present invention adopts a dynamic pulse width modulation frequency adjustment strategy, adaptively adjusts the pulse width modulation frequency by combining the current error and the temperature change rate, reduces the switching loss, and at the same time ensures the current stability. Compared with the existing fixed pulse width modulation frequency scheme, it reduces the loss of high-frequency switching, optimizes the energy utilization rate, solves the problem of additional heat loss caused by high-frequency driving, and significantly improves the energy efficiency ratio of the system.

[0056] 2. The present invention uses the discrete HJB optimal control algorithm to calculate the optimal pulse width modulation duty cycle in real time in combination with an embedded system, achieving high-speed closed-loop control. Compared with the traditional control method based on PID and fixed duty cycle, the present invention reduces the adjustment delay, can actively adapt to temperature fluctuations, improves the current calibration accuracy, and significantly improves the response speed and stability, especially in the scenario of dynamic load changes. Description of the Drawings

[0057] Figure 1 It is a schematic diagram of the overall process of the present invention;

[0058] Figure 2 It is a detailed flowchart of step S1 of the present invention;

[0059] Figure 3 It is a detailed flowchart of step S2 of the present invention;

[0060] Figure 4 It is a detailed flowchart of step S3 of the present invention;

[0061] Figure 5 It is a detailed flowchart of step S4 of the present invention;

[0062] Figure 6 It is a detailed flowchart of step S5 of the present invention. Detailed Embodiment

[0063] To enable those skilled in the art to understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0064] The following describes the present invention in detail with reference to the accompanying drawings:

[0065] Embodiment:

[0066] Please refer to the attached Figure 1 - attached Figure 6 , the embodiment of the present invention provides a solenoid valve current calibration control method considering temperature influence, including:

[0067] Step S1: Establish a solenoid valve current dynamics model;

[0068] Step 1.1, use Kirchhoff's voltage law to construct a solenoid valve current dynamics model to determine the relationship between the solenoid valve coil current, inductance, resistance, supply voltage, and pulse width modulation duty cycle;

[0069] Step 1.2: Establish a differential equation to describe the dynamic influence of the pulse width modulation duty cycle on the current. The differential equation is expressed as:

[0070] where I(t) is the solenoid valve coil current, R(T) is the resistance at temperature T, D(t) is the pulse width modulation duty cycle, L is the inductance of the solenoid valve coil, and U is the supply voltage;

[0071] Step 1.3: Combine the temperature-dependent resistance model to ensure that the current dynamics model can be adjusted by temperature changes;

[0072] Step S2: Construct a temperature-dependent coil resistance model;

[0073] Step 2.1: Based on experimental data, fit the relationship between temperature T and coil resistance R to obtain a temperature-dependent model: R(T) = R0(1 + α1(T - T0) + α2(T - T0) 2 )

[0074] where R0 is the resistance at the reference temperature T0, α1 and α2 are temperature coefficients, T is the current temperature, T0 is the reference temperature, and R(T) is the coil resistance at temperature T;

[0075] Step 2.2: Combine the current dynamics model, substitute the temperature model, and dynamically adjust the resistance parameters to ensure that the model can provide accurate resistance change information for setting the optimal control target;

[0076] Step S3: Set the optimal control target for solenoid valve current calibration;

[0077] Step 3.1: According to the models in Step S1 and Step S2, define the optimization objective function, considering the current error term and the energy consumption term. The objective function is:

[0078]

[0079] where I * is the target current, I(t) is the actual current, D(t) is the pulse width modulation duty cycle, w1 is the weight of the current error, w2 is the weight of the energy consumption, J is the optimization objective function, and t f is the termination time of the optimization process;

[0080] Step 3.2: Set the optimization constraint conditions to ensure that the maximum current and power of the solenoid valve are limited within a safe range and provide an optimization criterion for solving the optimal pulse width modulation duty cycle;

[0081] Step S4: Solve the optimal pulse width modulation duty cycle based on the HJB equation;

[0082] Step 4.1: Combining the optimization objective function, derive the HJB equation, construct the optimal value function V(x1, x2, t), and solve for the optimal pulse width modulation duty cycle D * (t). The HJB equation is as follows:

[0083]

[0084] where V(x1, x2, t) is the optimal value function, x1 = I(t) is the current current, x2 = T(t) is the current temperature, u = D(t) is the control variable, w1 is the weight coefficient of the current error, w2 is the weight coefficient of the energy consumption, R(x2) is the coil resistance dependent on the temperature x2, L is the inductance of the solenoid valve coil, U is the supply voltage, and f t is the influence model of the temperature change on the current dynamics;

[0085] Step 4.2: Combining the temperature model in Step S2, ensure that the solved pulse width modulation duty cycle can dynamically adapt to the temperature change and meet the optimization objective in Step S3;

[0086] Step 4.3: Solve for the optimal pulse width modulation duty cycle D * (t) through the optimal control theory and provide the optimal control signal for the current calibration control;

[0087] Step S5: Implement the solenoid valve current calibration control based on the optimal pulse width modulation duty cycle;

[0088] Step 5.1: Using the optimal pulse width modulation duty cycle obtained in Step S4, dynamically adjust the pulse width modulation signal to gradually approximate the actual current to the target current;

[0089] Step 5.2: Combining the temperature-dependent resistance model in Step S2, compensate for the influence of the temperature change on the pulse width modulation duty cycle in real time;

[0090] Step 5.3: Transmit the adjusted pulse width modulation signal to the solenoid valve drive circuit to achieve precise current calibration control and ensure that the optimization objective set in Step S3 is met.

[0091] 1. Establish the solenoid valve current dynamics model

[0092] First, starting from the physical characteristics of the solenoid valve, the present invention uses Kirchhoff's voltage law to establish the dynamic equation of the solenoid valve coil current. Since the coil has inductance and resistance characteristics, the driving voltage U generates a current I(t) through the coil and is jointly affected by the inductance L and the temperature-dependent resistance R(T). The dynamic relationship is expressed as:

[0093] Among them, D(t) is the duty cycle of pulse width modulation, which determines the average voltage applied to the coil. The resistance R(T) varies with temperature, affecting the current response speed and steady-state value.

[0094] The present invention conducts a dynamic analysis of the effect of the pulse width modulation duty cycle on the current, describes how the pulse width modulation signal affects the instantaneous change rate of the coil current, and provides a theoretical basis for subsequent optimization control. Traditional methods often ignore the effect of inductance, resulting in a lag in the control strategy. The present invention fully considers the influence of inductance on the dynamic response of the current, improving the model accuracy.

[0095] The present invention further considers the characteristic that the coil resistance R(T) varies with temperature, adopts the method of experimental fitting to establish a temperature-dependent model, and substitutes the temperature-dependent model into the current dynamics equation, enabling the current control system to dynamically adapt to temperature changes, preventing current drift, and improving the control accuracy.

[0096] 2. Construct a temperature-dependent coil resistance model

[0097] Traditional solenoid valve control methods often ignore the influence of coil self-heating on the resistance, resulting in the failure of the control strategy in high-temperature and low-temperature environments. The present invention uses the experimentally measured data of the resistance varying with temperature to fit a temperature-dependent model of the coil resistance, ensuring that it can truly reflect the actual working state. Compared with the linear model, the non-linear model can accurately describe the influence of temperature changes on the resistance, especially fitting the actual situation under high-temperature conditions and improving the compensation accuracy.

[0098] The present invention combines the temperature-dependent model with the current dynamics model, enabling the resistance value to be dynamically adjusted according to temperature changes. During the operation of the solenoid valve, even if the ambient temperature and coil self-heating cause the temperature to rise, the system can automatically adjust the control parameters to prevent the problem of current drop caused by the increase in resistance and ensure the control accuracy.

[0099] 3. Set the optimal control target for solenoid valve current calibration

[0100] The control target of the present invention is to make the solenoid valve coil current as close as possible to the target value while reducing the system energy consumption. The goal is to reduce the energy consumption of the pulse width modulation drive while ensuring the current accuracy, making the system energy-saving.

[0101] To ensure the feasibility of the control strategy, the present invention sets the following constraints:

[0102] The coil current cannot exceed the maximum allowable value to prevent overload;

[0103] The pulse width modulation duty cycle needs to be within a reasonable range to avoid over-driving and under-driving.

[0104] 4. Solve the optimal pulse width modulation duty cycle based on the HJB equation

[0105] Based on the optimal control theory, the present invention uses the HJB (Hamilton-Jacobi-Bellman) equation to solve the optimal pulse width modulation duty cycle, which can dynamically adjust the pulse width modulation signal, enabling the current to quickly converge to the target value while reducing energy consumption.

[0106] During the solution process of the HJB equation in the present invention, a temperature model is introduced, enabling the optimal pulse width modulation duty cycle to be dynamically adjusted according to temperature changes. For example, when the temperature rises and causes an increase in resistance, the system will automatically increase the pulse width modulation duty cycle to prevent the current from dropping and ensure the stability of the magnetic field strength.

[0107] The finally solved pulse width modulation signal of the present invention can accurately control the current to maintain it within the target range, optimize energy consumption, avoid excessive switching losses, and improve the energy efficiency of the system.

[0108] 5. Implement solenoid valve current calibration control based on the optimal pulse width modulation duty cycle

[0109] According to the optimal pulse width modulation signal solved from the HJB equation, the present invention adjusts the pulse width modulation duty cycle in real time to minimize the current error while ensuring the optimal energy consumption of the system.

[0110] The present invention compensates for the influence of temperature changes on the pulse width modulation duty cycle in real time through a temperature-dependent resistance model. For example, in a high-temperature environment, the pulse width modulation duty cycle is automatically increased to compensate for the current drop caused by the increase in resistance and ensure the stable operation of the solenoid valve.

[0111] Finally, the present invention transmits the optimized pulse width modulation signal to the drive circuit to control the solenoid valve coil current, so as to maintain accurate and stable control effects in different temperature environments and improve the reliability and energy efficiency of the system.

[0112] The solenoid valve current calibration control method is applicable to various different types of solenoid valve systems, and adapts to the working characteristics of different solenoid valves by adjusting parameters;

[0113] To adapt to different solenoid valve systems and dynamically parameterize the key characteristics of solenoid valves, an adaptive adjustment algorithm is adopted;

[0114] Parameter adaptive adjustment formula

[0115]

[0116] Where, θ i is the solenoid valve system model parameter, γ i is the parameter adjustment learning rate, J is the optimization objective function, is the partial derivative of the objective function with respect to the parameter, is the old parameter of the solenoid valve system model, New parameters for the solenoid valve system model.

[0117] The current calibration control method of the present invention is applicable to a single type of solenoid valve and can be widely applied to solenoid valve systems with different specifications and working modes. Through the parameter adaptive adjustment mechanism, the system can automatically match the characteristics of different solenoid valves without manual adjustment, greatly improving the versatility.

[0118] Traditional methods usually rely on fixed parameters, while the present invention adopts an adaptive adjustment algorithm to dynamically adjust key parameters by learning the working state of the solenoid valve in real time.

[0119] The control strategy of the present invention takes into account three core requirements: energy efficiency optimization, precise calibration, and environmental adaptability. Through intelligent pulse width modulation regulation and HJB optimal control, it effectively solves the problems of high energy consumption, control hysteresis, and weak temperature adaptability of traditional methods, enabling the solenoid valve to operate efficiently and stably under complex working conditions.

[0120] The pulse width modulation control frequency of the solenoid valve current calibration control method can be set according to specific application requirements to meet different requirements for control accuracy and current stability;

[0121] Dynamically adjust the pulse width modulation frequency f according to the control accuracy and current stability requirements PWM , and the dynamic adjustment pulse width modulation frequency model is as follows:

[0122] Based on the current error and the temperature change rate:

[0123]

[0124] Frequency selection based on the optimization control model:

[0125]

[0126] Switching loss model caused by frequency:

[0127] P switch (f PWM ) = E on ·f PWM + E off ·f PWM ,

[0128] where f PWM (t) is the real-time frequency of the pulse width modulation signal, f min , f max are the upper and lower limits of the pulse width modulation frequency, σ is the normalization function, k e is the current error weight coefficient, k T is the temperature change rate weight coefficient, J freqis the objective function for frequency optimization

[0129] w1, w2, and w3 are the weights of different factors in the optimization objective function, and E on , E off are the energies dissipated during each switching process, and P switch (f PWM ) is the switching power loss caused by the pulse width modulation frequency, I * is the target current, I(t) is the actual current, and T(t) is the current temperature.

[0130] Compared with the traditional fixed pulse width modulation frequency scheme, the present invention can adjust the pulse width modulation frequency in real time according to the current error and the temperature change rate, ensuring that the current can be accurately controlled under rapidly changing working conditions and improving the dynamic adaptability.

[0131] By optimizing the control model, the adjustment of the pulse width modulation frequency of the present invention improves the control accuracy and reduces the additional switching loss, enabling the system to greatly improve the energy efficiency ratio while ensuring the stability of the current.

[0132] The present invention incorporates the temperature-dependent model into the process of adjusting the pulse width modulation frequency, which can automatically optimize the control strategy in high and low temperature environments, avoid current drift or instability problems caused by temperature changes, and ensure that the solenoid valve always operates in the best state.

[0133] Different types of solenoid valve systems can adapt to the control method of the present invention by adjusting parameters without manual intervention, greatly improving the versatility and adaptability of the system.

[0134] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A solenoid valve current calibration control method considering temperature influence, characterized in that: include: Step S1: Establishing a solenoid valve current dynamics model; Step S2: constructing a temperature-dependent coil resistance model; Step S3: setting the optimal control target of the solenoid valve current calibration; Step S4: solving the optimal pulse width modulation duty cycle based on the HJB equation; Step S5: Implementing solenoid valve current calibration control based on the optimal pulse width modulation duty cycle.

2. The solenoid valve current calibration control method considering temperature influence according to claim 1, characterized in that: In the step S1, establishing the solenoid valve current dynamics model further includes: Step 1.1, construct a solenoid valve current dynamics model using Kirchhoff's voltage law to determine the relationship between the solenoid valve coil current, inductance, resistance, supply voltage and pulse width modulation duty cycle; Step 1.2, establish a differential equation to describe the dynamic effect of pulse width modulation duty cycle on current. The differential equation is expressed as: Where I(t) is the solenoid valve coil current, R(T) is the resistance at temperature T, D(t) is the pulse width modulation duty cycle, L is the inductance of the solenoid valve coil, and U is the supply voltage; Step 1.3, incorporating a temperature-dependent resistance model, ensures that the current kinetic model can be adjusted by temperature changes.

3. The solenoid valve current calibration control method considering temperature influence according to claim 1, characterized in that: In step S2, constructing the temperature-dependent coil resistance model further includes: Step 2.1, based on the experimental data, fit the relationship between temperature T and coil resistance R to obtain the temperature dependence model: R(T) = R0(1+α1(T-T0(+α2(T-T0) 2 ), Where R0 is the resistance at the reference temperature T0, α1 and α2 are temperature coefficients, T is the current temperature, T0 is the reference temperature, and R(T) is the coil resistance at temperature T; Step 2.2, combine the current dynamics model, substitute the temperature model, and dynamically adjust the resistance parameters to ensure that the model can provide accurate resistance change information for optimal control target setting.

4. The solenoid valve current calibration control method considering temperature influence according to claim 1, characterized in that: In step S3, setting the optimal control target of the solenoid valve current calibration further includes: Step 3.1, based on the models of step S1 and step S2, define the optimization objective function, considering the current error term and energy consumption term, the objective function is: Among them, I * is the target current, I(t) is the actual current, D(t) is the pulse width modulation duty cycle, w1 is the weight of the current error, w2 is the weight of the energy consumption, J is the optimization objective function, t f is the termination time of the optimization process; Step 3.2, set the optimization constraints to ensure that the maximum current and power limit of the solenoid valve are within a safe range and provide optimization criteria for solving the optimal pulse width modulation duty cycle.

5. The solenoid valve current calibration control method considering temperature influence according to claim 1, characterized in that: In step S4, solving the optimal pulse width modulation duty cycle based on the HJB equation further includes: Step 4.1, combined with the optimization objective function, derive the HJB equation, construct the optimal value function V(x1, x2, t and solve the optimal pulse width modulation duty cycle D * (t), the HJB equation is as follows: Among them, V(x1,x2,t) is the optimal value function, x1=I(t) is the current current, x2=T(t) is the current temperature, u=D(t) is the control variable, w1 is the weight coefficient of the current error, w2 is the weight coefficient of the energy consumption, R(x2) is the coil resistance that depends on the temperature x2, L is the solenoid valve coil inductance, U is the power supply voltage, f t Model the effect of temperature change on current dynamics; Step 4.2, combining the temperature model of step S2, ensuring that the solved pulse width modulation duty cycle can dynamically adapt to temperature changes and meet the optimization goal of step S3; Step 4.3, solve the optimal pulse width modulation duty cycle D through optimal control theory * (t), and provide an optimal control signal for current calibration control.

6. The solenoid valve current calibration control method considering temperature influence according to claim 1, characterized in that: In step S5, implementing the solenoid valve current calibration control based on the optimal pulse width modulation duty cycle further includes: Step 5.1, using the optimal pulse width modulation duty cycle obtained in step S4, dynamically adjusting the pulse width modulation signal so that the actual current gradually approaches the target current; Step 5.2, combining the temperature-dependent resistance model of step S2, to compensate the effect of temperature change on the pulse width modulation duty cycle in real time; Step 5.3, transmit the adjusted pulse width modulation signal to the solenoid valve drive circuit to achieve accurate current calibration control, while ensuring that the optimization target set in step S3 is met.

7. The solenoid valve current calibration control method considering temperature influence according to claim 1, characterized in that: The solenoid valve current calibration control method is applicable to various types of solenoid valve systems and can adapt to the working characteristics of different solenoid valves by adjusting parameters.

8. The solenoid valve current calibration control method considering temperature influence according to claim 7, characterized in that: In order to adapt to different solenoid valve systems and dynamically parameterize the key characteristics of the solenoid valve, an adaptive adjustment algorithm is used; The parameter adaptive adjustment formula Among them, θ i is the solenoid valve system model parameter, γ i is the parameter adjustment learning rate, J is the optimization objective function, is the partial derivative of the objective function with respect to the parameter, is the old parameter of the solenoid valve system model, New parameters for the solenoid valve system model.

9. The solenoid valve current calibration control method considering temperature influence according to claim 1, characterized in that: The pulse width modulation control frequency of the solenoid valve current calibration control method can be set according to specific application requirements to meet different control accuracy and current stability requirements.

10. The solenoid valve current calibration control method considering temperature influence according to claim 9, characterized in that: The pulse width modulation frequency f is dynamically adjusted according to the control accuracy and current stability requirements. PWM , the model for dynamically adjusting the pulse width modulation frequency is as follows: Based on current error and temperature change rate: Frequency selection based on optimal control model: Frequency-induced switching loss model: P switch (f PWM )=E on ·f PWM +E off ·f PWM , Among them, f PWM (t) is the real-time frequency of the pulse width modulation signal, f min 、f max is the upper and lower limits of the pulse width modulation frequency, σ is the standardization function, k e is the current error weight coefficient, k T is the weight coefficient of temperature change rate, J freq Optimize the objective function for frequency w1, w2, and w3 are the weights of different factors in the optimization objective function. on 、E off is the energy lost in each switching process, P switch (f PWM ) is the switching power loss caused by the pulse width modulation frequency, I * is the target current, I(t) is the actual current, and T(t) is the current temperature.

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